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Two eucalyptol derivatives, namely 1,3,3-trimethyl-2-oxabicycle[2.2.2]oct-5-yl acetate (4) and 1,3,3-trimethyl-2-oxabicycle[2.2.2]oct-5,8-yl acetate (6) have been synthesized and characterized. Their crystal structures have been solved by single-crystal X-ray diffraction methods indicating that the molecular conformation of both compounds is stabilized by intramolecular C–H⋯O bonds between the H-atoms of the methyl group from the eucalyptol moiety and the O-atom of the acetoxy group. In addition, we have performed a detailed investigation of the intermolecular interactions that stabilize the crystal packing of both structures by using Hirshfeld surface analysis and their associated two-dimensional fingerprint plots. The analysis reveals that the solid-state structure of compounds 4 and 6 is mainly stabilized by C–H⋯O hydrogen bonds and H⋯H bonding interactions. These interactions have also been described and studied energetically using DFT calculations. The nature and strength of these intermolecular contacts have been rationalized by using several computational tools including molecular electrostatic potential (MEP) surfaces, natural bond orbital analysis (NBO), Bader's theory of atoms in molecules (QTAIM) and non-covalent interaction plot (NCI plot) index methods. Furthermore, the intermolecular contacts observed in the crystal lattice of both compounds were experimentally studied through vibrational (IR and Raman) and 1H and 13C NMR spectra. The computational molecular docking analysis of the compounds has been carried out against five potential leishmanial drug targets and the main protease of SARS-CoV-2. [ABSTRACT FROM AUTHOR]

Abstract Sulfadiazine Co(II), Ni(II) and Cu(II) complexes have been synthesized and characterized. The crystal structure of the cobalt(II) complex, for short [Co(SDZ) 2 (DMF) 2 ], was determined by X-ray diffraction methods. It crystallizes in the monoclinic space group P 2 1 / c with Z = 2 molecules per unit cell. The complex is centre-symmetric with the metal at the centre of a rectangular bi-pyramid environment (CoN 4 O 2 core), coordinated at the bi-pyramid base to two SDZ molecules and at the apices to two DMF solvent molecules. The crystal structure determination was combined with Hirshfeld surface analysis to obtain detailed information on the intermolecular interactions that stabilizes the crystal packing. The nature and strength of the Co N and Co O bonds were investigated by the natural bond orbital (NBO) analysis and the atoms in molecules (AIM) approach. Based on NBO and AIM analysis, the shorter Co N4 bonds are more covalent in nature than Co O bonds. The antibacterial assays of the metal complexes revealed lower activity than the free ligand, probably due to their low solubility in water. However, their low toxicity as compared with SDZ makes them potential alternatives against other microorganisms, and/or biological targets. Graphical abstract Image 1 Highlights • Co(II), Ni(II) and Cu(II) ternary complexes with Sulfaziadine and dimethylformamide as ligands have been synthesized. • The crystal structure of the Co(II) complex was determined by XRD methods. • Antibacterial activity of the ligand and complexes was evaluated. [ABSTRACT FROM AUTHOR]

The crystal structure of pyridinium 6-methyl-1,2,3,-oxathiazine-4(3H)-one-2,2-dioxide [(C5NH6)(C4H4NO4S)], for short, pyH(ace), was determined by X-ray diffraction methods. It crystallizes as a twin in the monoclinic space group P21/c with a=6.9878(9), b=7.2211(7), c=21.740(2) Å, β=91.67(1)° and Z=4 molecules per unit cell. The structure was determined employing 1599 reflections with I>2σ(I) from one of the twin domains and refined employing 2092 reflections from both crystal domains to an agreement R1 factor of 0.0466. Besides electrostatic attractions, intermolecular pyH···O=C(ace) hydrogen bonds stabilize the acesulfamate anion and the pyridinium cation into planar discrete units parallel to the (100) crystal plane. The units form stacks of alternating ace− and pyH+ ions along the a axis that favors inter-ring π–π interactions. The Fourier transform-infrared (FT-IR) spectrum of the compound was recorded and is briefly discussed. Some comparisons with related pyridinium saccharinate salts are also made. [ABSTRACT FROM AUTHOR]

Attenuated total reflectance (ATR) from principal faces of orthorhombic (and higher symmetry) crystals in spectral regions including strongly polar optic modes is considered. A detailed, quantitative comparison between experimental and calculated ATR infrared (IR) spectra of orthorhombic sodium nitroprusside dihydrate (SNP), Na2[Fe(CN)5NO]·2H2O, single crystals in the 500–3800 cm-1 region is presented. Calculated ATR spectra are generated employing the dielectric tensor of SNP obtained from Kramers–Kronig analysis of external reflectance data. The dependence of intensities, profiles, and locations of bands in the spectra upon the relative refractive index of the sample against the ATR prism and the polarization state of the reflected IR beam will be discussed. Both theoretical and experimental evidence of the coupling of the TM-polarized evanescent wave with strong in-plane-polarized optic modes at about their LO frequencies will be given with reference to the case of the strong NO stretching mode of SNP. Finally, the computed and experimental ATR results in SNP single crystals will be critically compared with powder ATR data and reported polarized IR transmittance spectra of SNP single crystals plates. [ABSTRACT FROM AUTHOR]

The term ‘organic minerals’ means naturally occurring crystalline organic compounds including metal salts of formic, acetic, citric, mellitic, methanesulfonic and oxalic acids. As for the rest of the (inorganic) minerals, the primary tool to disclose their crystal and molecular structure and therefore to understand their mutual relationship with each other and with synthetic analogues and also their physicochemical properties is X-ray diffraction crystallography ever since the dawn of this methodology in 1913. The structure of several synthetic organic minerals was solved well before the discovery of their natural counterpart. On the other hand, complete crystal structure determination of early discovered organic minerals had to await the advent of combined synthetic and advanced X-ray diffraction methods to fully unveil their crystal structures. We review here the crystal chemistry of organic minerals and show the importance of structural studies on their synthetic analogues. This will be highlighted by case studies on the recently reported synthetic novgorodovaite, Ca2(C2O4)Cl2·2H2O, and its heptahydrate analogue, Ca2(C2O4)Cl2·7H2O, and the isotypic to each other stepanovite, NaMg[Fe(C2O4)3]·9H2O, and zhemchuzhnikovite, NaMg[AlxFe1−x(C2O4)3]·9H2O. [ABSTRACT FROM AUTHOR]

Synthetic novgorodovaite analog Ca2( C2O4) Cl4·2H4O is identical to its natural counterpart. It crystallizes in the monoclinic I2/m space group with a = 6.9352(3), b = 7.3800(4), c = 7.4426(3) Å, β = 94.303(4)°, V = 379.85(3) Å3 and Z = 2. The heptahydrate analog, Ca2( C2O4)Cl4·7H4O, crystallizes as triclinic twins in the P1 space group with a = 7.3928(8), b = 8.9925(4), c = 10.484(2) Å, α = 84.070(7), β = 70.95(1), γ = 88.545(7)°, V = 655.3(1) Å3 and Z = 2. The crystal packing of both calcium oxalate-chloride double salts favors the directional bonding of oxalate, C2O4 2-, ligands to calcium ions as do other related calcium oxalate minerals. The π-bonding between C and O atoms of the C2O4 2- oxalate group leaves sp2-hydridised orbitals of the oxygen atoms available for bonding to Ca. Thus, the Ca-O bonds in both calcium oxalate-chloride double salts are directed so as to lie in the plane of the oxalate group. This behavior is reinforced by the short O...O distances between the oxygens attached to a given carbon atom, which favors them bonding to a shared Ca atom in bidentate fashion. Strong bonding in the plane of the oxalate anion and wide spacing perpendicular to that plane due to repulsion between oxalate π-electron clouds gives rise to a polymerized structural units which are common to both hydrates, explaining the nearly equal cell constants ~7.4 Å which are defined by the periodicity of Ca-oxalate chains in the framework (monoclinic b ≈ triclinic a). When compared with novgorodovaite, the higher water content of Ca2( C2O4) Cl4·7H4O leads to some major differences in their structures and ensuing physical properties. While novgorodovaite has a three-dimensional framework structure, in the higher hydrate, the highly polar water molecules displace chloride ions from the calcium coordination sphere and surround them through OwH···Cl hydrogen bonds. As a result, polymerization in Ca2( C2O4)Cl4·7H4O solid is limited to the formation of two-dimensional Ca2( C2O4)(H4O)5 slabs parallel to (001), inter-layered with hydrated chloride anions. This layered structure accounts for (001) being both a perfect cleavage and a twin interface plane. The infrared and Raman spectra of both salts are also briefly discussed. [ABSTRACT FROM AUTHOR]

In spite of the apparent contradiction between ‘liquid crystals’ (LC, materials exhibiting some degree of disorder) and ‘crystallography’ (a paradigmatic ordered kingdom), X-ray diffraction (XRD) studies make a substantial contribution to the field of LC. Focusing this review on smectic (Sm, lamellar) LC, we first describe how extremely careful XRD studies performed on mono-domain samples in the LC phase helped to elucidate the molecular structure of ordered Sm phases. Then, we describe selected examples in which single-crystal (SC) XRD on the solid-state phase of the mesogens provided information about their supra-molecular organization in the Sm phase. Finally, we present a different approach to this problem in the case of a thermo-tropic Schiff base (SB) which undergoes crystal ↔ LC ↔ isotropic liquid phase transformations. By combined SC and variable-temperature powder XRD, we show that the SB LC is a hexatic smectic B phase that derives from the crystal phase by relatively small topological changes promoted by the set-in of thermal rotational disorder around the long SB molecular axis. [ABSTRACT FROM AUTHOR]

The crystal structure of aqua lithium 6-methyl-1,2,3,-oxathiazine-4(3H)-one, 2.2-dioxide, for short Li(ace)HO, was determined by X-ray diffraction methods. It crystallizes in the triclinic P $$\overline {1}$$ space group with a = 6.1750(9) Å, b = 7.3969(9) Å, c = 9.016(1) Å, α = 105.88(1)°, β = 94.59(1)°, γ = 97.80(1)°, and Z = 2 molecules per unit cell. The crystal structure of Li(ace)HO sharply departs from the other heavier alkaline-metal acesulfamates, namely the monoclinic isotypic M-ace (M from Na to Cs) family of salts. Lithium is in a distorted LiO tetrahedral coordination with acesulfamate carbonyl, sulfoxide and water oxygen atoms. The FTIR spectrum of the new compound was also recorded and is briefly discussed. Some comparisons with other simple acesulfamate salts are also made. Graphical Abstract: The synthesis of aqua lithium acesulfamate, Li(CHNOS)HO, and its structural characterization by single-crystal X-ray diffractometry are reported. The FTIR spectrum of the salt is analyzed by comparison with data of related compounds. [ABSTRACT FROM AUTHOR]

Cadmium and lead(II) acesulfamate, Cd(C4H4NO4S)2 · 2H2O and Pb(C4H4NO4S)2, were prepared by the reaction of acesulfamic acid and the respective metal carbonates in aqueous solution, and characterized by elemental analysis. Their crystal structures were determined by single crystal X-ray diffraction methods. The Cd(II) compound crystallizes in the monoclinic space group P21/c with Z = 4 and the corresponding Pb(II) salt in the triclinic space group P1 with Z = 2. In both salts, acesulfamate acts both as a bi-dentate ligand through its nitrogen and carbonyl oxygen atoms and also as a mono-dentate ligand through this same oxygen atom, giving rise to polymeric structures; in the Pb(II) salt the ligand also binds the cation through its sulfoxido oxygen atoms. The FTIR spectra of the compounds were recorded and are briefly discussed. Some comparisons with other related acesulfamate and saccharinate complexes are made. [ABSTRACT FROM AUTHOR]

A new general synthetic procedure for preparation of Na3[Fe(C2O4)3]·5H2O (1), Rb3[Fe(C2O4)3]·3H2O (2), and Cs3[Fe(C2O4)3]·2H2O (3) was developed. The crystal structures of these salts have been determined by single crystal X-ray diffraction. Salt1crystallizes in the monoclinic space group C2/cwithZ = 8, salt2in P21/cwithZ = 4, and salt3in P21/nwithZ = 4. The three new salts and K3[Fe(C2O4)3]·3H2O, prepared for comparative purposes, were further characterized by infrared and57Fe-Mössbauer spectroscopy. These spectra are discussed in comparison with those of related oxalato complexes. [ABSTRACT FROM AUTHOR]

In February 1912 in Munich, P. P Ewald, one of A. Sommerfeld's Ph.D. students, consulted M. Laue on matters related to crystal optics, his thesis subject. During the conversation, Laue conceived the idea that a crystal might act as a three-dimensional diffraction grating to the X-rays. Despite the idea having met with scepticism among his colleagues, Laue succeeded in getting the help of two of W. C. Roentgen's doctorands: F. Friedrich, Sommerfeld's laboratory assistant, and P. Knipping: to undertake the, by now, legendary experiments that originated a new branch of Physics. The results solved two fundamental questions of the time: namely are the X-rays electromagnetic radiation (light) of very short wavelength? And also, do the crystals have spatial periodic arrangements? The affirmative answer to both questions was immediately followed in 1913 by the instrumentation and re-interpretation of the phenomenon through the pioneering work by W. H. Bragg and his son W. L. Bragg, who paved the way to the portentous development of structural crystallography by X-ray diffraction that took place during the last hundred years. [ABSTRACT FROM PUBLISHER]

The crystal structure of synthetic stepanovite, Na[Mg(HO)][Fe(CO)]·3HO, and zhemchuzhnikovite, Na[Mg(HO)][AlFe(CO)]·3HO, has been determined by single-crystal X-ray diffraction methods. The compounds are isotypic to each other and to the previously reported Na[Mg(HO)][M(CO)]·3HO (M: Cr, Al). They crystallize in the trigonal P3 c1 space group with Z = 6 molecules per unit cell and (hexagonal axes) a = 17.0483(4), c = 12.4218(4) Å for the iron compound, and a = 16.8852(5), c = 12.5368(5) Å for the Al/Fe solid solution. Comparison of our crystallographic results with previous X-ray diffraction and chemical data of type stepanovite and zhemchuzhnikovite minerals provides compelling evidence that these natural materials possess the same crystal and molecular structure as their synthetic counterparts. It is shown that the originally reported unit cell for stepanovite represents a pronounced sub-cell and that the correct unit cell and space group are based on weak superstructure reflections. The infrared and Raman spectra of both synthetic analogs were also recorded and are briefly discussed. [ABSTRACT FROM AUTHOR]

Magnesium acesulfamate, Mg(C4H4NO4S)2·6H2O, was prepared by the reaction of acesulfamic acid and magnesium carbonate in aqueous solution, and characterized by elemental analysis. Its crystal structure was determined by single crystal X-ray diffraction methods. The substance crystallizes in the triclinic space group P1̅ with one molecule per unit cell. The FTIR spectrum of the compound was also recorded and is briefly discussed. Some comparisons with other simple acesulfamate and saccharinate salts are also made. [ABSTRACT FROM AUTHOR]

The crystal structure of sodium and magnesiumtris(oxalato)chromato(III) nona hydrate, NaMg[Cr(C2O4)3]·9H2O, has been determined by X-ray diffraction methods. It crystallizes in the trigonalP3c1 space group with (in the hexagonal setting)a = b = 16.9635(4),c = 12.5247(3) Å, andZ = 6 molecules per unit cell. The Cr(III) and sodium ions are in octahedral environments coordinated to three oxalate molecules and arranged in a honeycomb-like layered structure perpendicular to the crystalc-axis. There are three different octahedral [Mg(H2O)6]2+hydrated ions that fill the honeycomb holes giving rise to electrically neutral Na[Mg(H2O)6][Cr(oxalato)3] crystal slabs. Neighboring slabs are bridged by the remaining three water molecules through H-bonds and therefore the whole crystal can be more properly described as Na[Mg(H2O)6][Cr(oxalato)3]·3H2O. Also, the structure of isomorphous NaMg[Al(C2O4)3]·9H2O compound has been re-examined and compared with the chromium(III) complex. Infrared and Raman spectra of both complexes were also recorded and briefly discussed. [ABSTRACT FROM PUBLISHER]

Three new acesulfamate salts, NaC4H4NO4S, RbC4H4NO4S and CsC4H4NO4S, were prepared by reactions in aqueous solutions and thoroughly characterized. Their crystal and molecular structures were determined by single crystal X-ray diffraction methods. They crystallize in the monoclinic space group P21/a with a = 7.2518(2), b = 8.9414(4), c = 10.5929(4) Å, β = 99.951(3)°, V = 676.52(4) Å3 for the Na salt; a = 7.4663(3), b = 9.6962(4), c = 10.4391(4) Å, β = 95.150(3)°, V = 752.68(5) Å3 for the Rb salt and a = 7.5995(4), b = 9.9439(4), c = 10.8814(6) Å, β = 91.298(5)°, V = 822.08(7) Å3 for the Cs salt, and Z = 4 molecules per unit cell. The three compounds are isotypic to each other and to the previously reported potassium salt. The metal ions are in irregular polyhedral coordination with six neighboring acesulfamate anions through their nitrogen and carbonyl and sulfoxide oxygen atoms. The FTIR spectra of the compounds were also recorded and are briefly discussed. [ABSTRACT FROM AUTHOR]

The title compound was prepared by reaction, in aqueous solution, of Tl2CO3 and H2C2O4·2H2O in a molar ratio of 1:2. Its crystal structure was solved by X-ray diffraction methods. It crystallizes in the monoclinic space group P21/a with Z = 2 molecules per unit cell. The oxalic acid molecule and the oxalate anion are planar, residing on crystallographic inversion centers, and linked to each other by strong O–H···O hydrogen bonds giving rise to a polymeric structure. The Tl(I) ion is in a distorted polyhedral coordination with nine neighboring O atoms, five of oxalate anions and four others of oxalic acid molecules. The FTIR and FT-Raman spectra of the compound were also recorded and are briefly discussed. [ABSTRACT FROM AUTHOR]

Highlights: [•] The molecular structure of the compound has been determined by X-ray diffraction. [•] The substance crystallizes in the monoclinic P21/c space group with Z =8 molecules per unit cell. [•] The conformers are arranged in the lattice as center-symmetric N H⋯O(sulf) bonded dimers. [•] For NBO analysis, the hyperconjugative interactions are favored in conformer 2 than conformer 1. [•] Infrared and Raman spectra showed bands assignable to 34 of the 36 vibrational normal modes. [ABSTRACT FROM AUTHOR]

The molecular structure of two mixed and closely related conformers of the title compound, C13H16O2, found in the solid with unequal occupancies has been determined by X-ray diffraction methods. The substance crystallizes in the monoclinic Pca21 space group with a =17.279(2), b =5.1716(7), c =12.549(2)Å, and Z = 4 molecules per unit cell. The structure was solved from 1314 reflections with I >2σ(I) and refined to an agreement R1-factor of 0.049. The minor conformer (34.7%) is nearly mirror-related to and extensively overlapped with the major one. The skeleton of the 4-hydroxyacetophenone molecular fragment and the prenyl group,—(CH2)—(CH) = C(CH3)2, pendant arm attached to it are both planar and perpendicular to each other. A strong intermolecular O—H···O bond links neighboring molecules in the lattice to produce a polymeric structure. The conformational structures of the compound in the gas phase have been calculated by the DFT method and the geometrical results have been compared with the X-ray data. These data allow a complete assignment of vibration modes in the solid state FTIR and Raman spectra. The calculated 1H and 13C chemicals shifts are in good agreement with the corresponding experimental NMR spectra of the compound in solution. [Copyright &y& Elsevier]

Reaction of trans-Ru(DMSO)4C12 with DMAP (DMAP = 4-dimethylaminopyridine) yields the yellow [Ru(DMAP)6]2~ cation in good yield. The crystal and molecular structure of [Ru(DMAP)6]Cl2.6CH3CH2OH was determined by X-ray diffraction methods. The complex crystallizes in the trigonal F~3 space group with a = b = 16.373(1), c = 20.311(1) A, y = 120°, and Z = 3 molecules per unit cell. The reaction of [Ru(DMAP)6]2~ in aerobic water gives the red [Ru'°(DMAP)5(OH)]2~ cation. This complex shows a chemical behavior similar to [Ru'°(NH3)5Cl]2~ and allows the preparation of a family of [Ru(DMAP)5L]'~ complexes. Their electronic properties indicate that the {Ru°(DMAP)5} fragment is a weaker 7r-donor than {Ru"(NH3)5}. Our density functional theory (DFT) calculations show that in {RuH(DMAP)5} the DMAP ligands can compete for the ~r electron density of the ruthenium making the fragment a weaker ir-donor. [ABSTRACT FROM AUTHOR]

Abstract: A series of indazole N 1-oxide derivatives has been spectroscopically studied in solution using 1H, 13C, and 15N NMR based on pulsed field gradient selected PFG 1Hsp sp="0.25" />= 13C and 15N) gHMQC and gHMBC experiments. Some indazoles were prepared using a new methodology to compare its spectral and structural data with the indazole N 1-oxide parent compounds. The 13C resonances of the indazole N 1-oxide carbon 3 and 7a demonstrate the N-oxide push-electron capability. The 15N resonances of the indazole N-oxide, nitrogen 1, are near to 30ppm more shielded than the corresponding values in the indazole heterocycle (deoxygenated form). Moreover, the structures of one indazole and one indazole N-oxide were unambiguously confirmed by X-ray crystallography. The solid state structures were contrasted with the theoretical ones obtained in vacuo at different calculus level. The aromaticity of the derivatives was studied analyzing the Hg constants of indazole’s aromatic hydrogens and measuring Ces in the solid state. The fragmentation that takes place in EI/MS was gathered for all the indazole N-oxide derivatives and the general fragmentation pattern analyzed. [Copyright &y& Elsevier]

Abstract: The novel complex, C(NH2)3[VO2(dipic)]·2H2O (1), and its analogous, NH4[VO2(dipic)] (2), were synthesized and characterized in the solid state by means of FT-Raman and FT-infrared spectroscopies. Their crystal and molecular structures were determined by X-ray diffraction methods. The optimized geometry of the [VO2(dipic)]− anion and its corresponding harmonic vibrational frequencies were calculated using methods of the density functional theory. The [VO2(dipic)]− anion in both salts show a similar penta-coordinated environment. The planar dipic2− ligand coordinates to the moiety through one oxygen of each carboxylate and the nitrogen atom. Slight but significant differences between the bonding structures in both compounds were observed. The crystal structures are stabilized by hydrogen bridging interactions. [Copyright &y& Elsevier]

Abstract: 2-Benzoylpyridine semicarbazone (H2BzPS) and its complexes [Cu(H2BzPS)Cl2] (1) and [Zn(H2BzPS)Cl2] (2) have been synthesized and their spectral properties have been studied. The electrochemical behaviour of [Cu(H2BzPS)Cl2] (1) has been investigated. [Cu(H2BzPS)Cl2] (1) crystallizes in the triclinic P-1 space group, a=9.278(1), b=12.848(1), c=13.923(1) Å, α=84.54(1), β=71.91(1), γ=85.14(1)°, with two complexes per asymmetric unit (Z=4) and a disordered methanol solvent molecule (occupancy=1/4). [Zn(H2BzPS)Cl2] (2) crystallizes in the orthorhombic P212121 space group with a=11.983(1), b=14.067(1), c=18.706(1) Å, and two independent molecules per asymmetric unit (Z=8). In both cases, the neutral semicarbazone acts as a tridentate ligand which coordinates the metal through the pyridine and imine nitrogen atoms and the carbonyl oxygen. Two chloride ions occupy the fourth and fifth coordination positions. [Copyright &y& Elsevier]

The reactions of n-butylamine (BuNH2), 2-aminoethanol (H2N(CH2)2OH), diethylamine (Et2NH), and phenylhydrazine (PhN2H3) with 3,4-diphenyl-(1a) and phenanthro[9,10-c]-1,2,5-thiadiazole 1,1-dioxide (1b) were studied by cyclic voltammetry (CV) and 1H- and 13C-NMR in aprotic solvent solution. The course of the reactions depended on the substrate-nucleophile combination: Et2NH added to 1a or 1b, forming the corresponding thiadiazolines in an equilibrium monoaddition reaction. The equilibrium constants were evaluated and compared. With primary amines and PhN2H3, the nucleophile added to both C&dbond;N double bonds of 1a and displaced the sulfamide moiety. In the case of the reaction of 1a with PhN2H3, the intermediate monoaddition thiadiazoline, 3-(2-phenylhydrazino)-3,4-diphenyl-1,2,5-thiadiazoline 1,1-dioxide, was also isolated. BuNH2 and H2N(CH2)2OH reacted with 1a to give α-bis-imines, while 1a with PhN2H3 gave the α-bis-hydrazone. The configurations of benzil bis(ethanolimine) and benzilosazone were determined by single crystal x-ray diffraction analysis as Z,Z. BuNH2 and PhN2H3 reduced 1b to the corresponding thiadiazoline compound 1bH2. Copyright © 2006 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The structure of two perhalomethylated chromones, 2‐chlorodifluoromethylchromone (a) and its 6‐nitro substituted derivative (b), are investigated. The supramolecular assembly is governed by the hydrogen bond interaction (C−H···O) between the olefinic proton (OC−C(=C<)‐H) and the carbonyl oxygen atom (>C=O) giving rise to center‐symmetric R22(8)$R_2^2(8)$ graph‐set motifs. The H···O interatomic distance is shorter in (b) suggesting a stronger hydrogen bonding for this derivative. Quantum Theory of Atoms in Molecules (QTAIM) and natural bond orbital (NBO) calculated energies and the higher polarity computed for (b) agree with this experimental finding. The Molecular Electrostatic Potential (MEP) graph shows a distinctive C···Cl contact, found only for (b), involving a more electrophilic methine carbon atom. [ABSTRACT FROM AUTHOR]

The habit and the infrared spectra of the crystals obtained below 15 ºC (K 3 [Cr(CN) 5 NO].2H 2 O) and above 20 ºC (K 3 [Cr(CN) 5 NO]). • Accurate metrics of [CrI(CN) 5 NO]3- complex in its dihydrate potassium salt. • Advanced X-ray data collection and space group and structure solution and refinement. • K 3 [Cr(CN) 5 NO].2H 2 O isomorphic to the Mn(I) analogue. • IR and Raman spectra with assignment of water modes assisted by deuterium-enrichment. Potassium pentacyanonitrosylchromate(I) dihydrate salt, K 3 [Cr(CN) 5 NO].2H 2 O, forms spontaneously from aqueous solution below about 15 °C while the anhydrous salt is obtained above 20 °C. The molecular structure of the dihydrate has been determined by X-ray diffraction, taking full advantage of modern data collection, advanced space group and structure solution and refinement. It crystallizes in the monoclinic space group Cc , is isomorphic to the Mn(I) analog, and shows the pseudo-symmetry of space super-group C 2/ c. The [Cr(CN) 5 NO]3− ion has an umbrella-like conformation with the equatorial Cr-CN bonds slightly bent away from the Cr-NO link. The crystallographic study fills a gap left in the literature on accurate structural data for alkaline and alkaline-earth salts of [M(CN) 5 NO] n- (M = V, Cr, Mn, Fe) series of coordination compounds. We also report here the solid-state vibration structure of the new compound, as probed by IR and Raman spectroscopy. Water mode assignments were assisted through deuterium enrichment. The thermal dehydration behavior complements structural and spectroscopic information on water molecules. [ABSTRACT FROM AUTHOR]

The crystal structure of tetraaqua-bis(6-methyl-1,2,3-oxathiazin-4(3H)-onato 2,2-dioxide) copper(II) complex, for short [Cu(ace) 2 (H 2 O) 4 , was determined by X-ray diffraction methods. The complex crystallizes in the monoclinic C2/c space group with a = 11.9838(4), b = 9.5240(3), c = 15.1686(6) Å, β = 102.975(4)° and Z = 4 molecules per unit cell. The structure was determined from 1609 reflections with I > 2σ(I) and refined to an agreement R1-factor of 0.0345. [Cu(ace) 2 (H 2 O) 4 is a new member in the family of acesulfamate complexes of first row transition metals, namely [M(ace) 2 (H 2 O) 4 , M: Co, Ni, Zn. It differs from the other members in the bonding of acesulfamate to metal through one of its sulfoxide oxygen atoms. The new complex was further characterized by its infrared, Raman and electronic absorption spectra, which were discussed in comparison with those of other related species. Image 101 • A new Cu(II) acesulfamato complex, [Cu(acesulfamato) 2 (H 2 O) 4 , was obtained. • It crystallizes in the monoclinic C2/c space group with Z = 4. • Bonding of acesulfamate to Cu(II) occurs through one of its sulfoxide O-atoms. • FTIR, Raman and electronic spectra were recorded and discussed. • Comparisons with related complexes were made. [ABSTRACT FROM AUTHOR]

• Novel poly-thiolactone synthesis with endocyclic ether, polyether, and lactone groups. • Controlled thioester bond formation using diacyl chlorides and organometallic tin compounds. • Preparation of diverse polythiolactones including cyclo and spiro compounds. • Single-crystal X-ray diffraction reveals structural characteristics based on ring size and functional groups. • Crystal packing governed by C-H···O hydrogen bonding and van der Waals interactions, forming unique tubular arrangements. The synthesis and isolation of new thiolactone species containing endocyclic ether, polyether, and lactone groups were designed using the reaction between diacyl chlorides with organometallic tin compounds as a template for controlled thioester bond formation. Thus, eight polythiolactones, including cyclo and spiro compounds with different ring sizes and functional groups were prepared, namely 1-oxa-4,9-dithiacycloundecane-5,8-dione (1a), 1-oxa-4,10-dithiacyclododecane-5,9-dione (1b), 1,4-dioxa-7,12-dithiacyclotetradecane-8,11-dione (2a), 1,4-dioxa-7,13-dithiacyclopentaecane-8,12-dione (2b), 2,15,19,32-tetraoxa-6,11,23,28-tetrathia-spiro[16.16]tritriacontane 3,7,10,14,20,24,27,31-octaone (3a), 2,16,20,34-tetraoxa-6,12,24,30-tetrathia-spiro[17.17]pentatriacontan-3,7,11,15,21,25,29,33-octaone (3b), 9,12,25,28-tetraoxa-6,15,22,31-tetratia-1(1,4),17(1,4)-diphenylcyclodotriacontane-5,16,21,32-tetraone (2c), and 2,17,21,36-tetraoxo-6,13,25,32-tetrathia-8(1,4)27(1,4)-diphenyl-spiro[18-18]heptatriacontane-3,7,12,16,22,26,31,35-octaone (3c). The structural characteristics of the eight closely related derivatives were determined by examining the impact of ring size and functional groups, through single-crystal X-ray diffraction techniques. The crystal packing of these polythiolactones was found to be mainly governed by weak C-H···O hydrogen bonding and van der Waals interactions, resulting in partially overlapping tubular arrangements. Hirshfeld analysis was performed to investigate the crystal packing and intermolecular interactions. The results of this study show the possibility of forming 3D tubular arrangements using polythiolactones with various endocyclic groups, including both flexible and rigid spacers. [Display omitted] [ABSTRACT FROM AUTHOR]

Two new transition metal complexes with 1-methylimidazole (1-MeIm) and azide as ligands, namely, [Co(1-MeIm)4(N3)2] (1) and [Ni(1-MeIm)4(N3)2] (2), have been synthesized and characterized by IR, Raman, UV-Vis and XPS spectroscopy. Their crystal structures were solved by single-crystal X-ray diffraction. The supramolecular self-assembly of the two complexes is governed by non-classical C–H⋯N hydrogen bonds and C–H⋯π interactions. Lattice energies and intermolecular interaction energies for various molecular pairs are quantified using the PIXEL method. DFT computational studies to assess the binding energy through modern tools like non-covalent interaction (NCI plots) analysis and reduced density gradient (RDG) analysis have also been carried out. A detailed analysis of geometric descriptors revealed the existence of quasi-isostructural pairs or 'main-part' isostructuralism in a series formed by 1, 2, and a related cadmium complex, being more evident in the 1/2 pair. DFT studies using theoretical models have been used to disclose the relative importance of the H-bond and C–H⋯π noncovalent interactions. Magnetic measurements for compound 1 show weak ferrimagnetic coupling between adjacent M(II) centers, mediated by H-bonding and C–H⋯π non-covalent interactions. [ABSTRACT FROM AUTHOR]

Addresses the error made on correlation lines in the attenuated total reflectance infrared spectra of strongly absorbing anisotropic crystals.

Five new transition metal nitroprussides with 1-methylimidazole (1-MeIm) have been synthesized and characterized by IR, XPS and UV-vis spectroscopy, thermal analysis, and powder and single-crystal X-ray diffraction. The structural analyses have revealed that the complexes Mn(1-MeIm)2[Fe(CN)5NO] (1), Fe(1-MeIm)2[Fe(CN)5NO] (2), Cu(1-MeIm)4[Fe(CN)5NO] (3), Zn(1-MeIm)2[Fe(CN)5NO] (4) and Cd(1-MeIm)2[Fe(CN)5NO] (5) are 2D coordination polymers. The supramolecular self-assembly of all the five complexes is governed by non-classical C–H⋯N hydrogen bonds and lone-pair(O)⋯π interactions. N⋯O chalcogen and π⋯π contacts are also present in the crystal packing of complexes 1, 2, 4 and 5. A detailed analysis of four geometric descriptors revealed the existence of a high degree of isostructurality for the molecular pair 1/2, and a moderate one for the pairs 1/5 and 2/5. The dissimilarity index was also calculated for molecular pairs in two series of related compounds, showing that the degree of similarity is lower than those found in the pairs 1/2, 1/5 and 2/5. The results herein discussed for first time in the literature may be useful to understand property/structure relationships in these types of complexes. By using DFT calculations at the PBE0-D3/def2-TZVP level of theory and discrete models of the coordination polymers, we have analyzed cooperative lp–π/π–π/π–lp assemblies that are observed in the solid state of these compounds. This interesting assembly has been further analyzed by a combination of QTAIM, NCIplot and MEP surface calculations. The magnetic measurements indicate that compounds 1–3 are paramagnetic at 300 K and the Curie–Weiss constants are negative, suggesting weak antiferromagnetic coupling between the metal centers, at very low temperatures. [ABSTRACT FROM AUTHOR]

A new series of CuII, NiII, CoII, and MnIII complexes have been synthesised from the (6 Z)-6-(7-trifluoromethyl-1,2,3,4-tetrahydro-5 H -1,4-diazepin-5-ylidene)cyclohexa-2,4-dien-1-one (HDZP) ligand. These complexes were characterised by elemental, spectroscopic (IR and UV-vis), and thermal analysis. The crystal structure of Cu-DZP was solved by X-ray diffraction methods. The complex crystallises in the monoclinic P 21/ c space group, with two molecules per unit cell. The crystal lattice is stabilised by different intra and intermolecular interactions. Hirshfeld surface analysis was employed to obtain additional information about interactions that are responsible for the crystal packing. Quantitative examination of the fingerprint plots indicated the dominant contribution of H⋯H and H⋯X (X = O, F) interactions in the crystal packing. In addition, C–H⋯chelate ring (CR) and C–H⋯π interactions are described in detail and evaluated using DFT calculations. The antibacterial properties and the mechanism of inhibition of the main bacterial resistant mechanism, the biofilm, of the metal complexes and free ligand were investigated. [Mn(DZP)3]·2H2O was the most active complex against the Pseudomonas aeruginosa biofilm formation with an inhibition of 40 %. However, none of the complexes inhibit more than 25 % of the Gram negative bacteria microbial development. The most meaningful result was the bactericidal effect of [Co(DZP)2(H2O)2]·2H2O against the Gram positive bacteria, Staphylococcus aureus , which inhibits the bacterial development and significantly reduces the biofilm formation at low concentration. A new series of CuII, NiII, CoII, and MnIII complexes have been synthesised from the (6 Z)-6-(7-trifluoromethyl-1,2,3,4-tetrahydro-5 H -1,4-diazepin-5-ylidene)cyclohexa-2,4-dien-1-one (HDZP) ligand. These complexes were characterised by elemental, spectroscopic (IR and UV-vis), and thermal analysis. The crystal structure of Cu-DZP was solved by X-ray diffraction methods. [ABSTRACT FROM AUTHOR]

The synthesis of four novel amide compounds (R1C(O)NHR2) is reported, which contain both bulky (R1=phenyl and adamantyl) and hydrophilic (R2=hydroxyl, methoxyl) groups. The incorporation of such substituents provides compounds with unique properties that combine steric hindrance and hydrophilicity. The synthesized amides were fully characterized by 1H and 13C nuclear magnetic resonance (NMR) and analysed using infrared (IR) and Raman spectroscopy to investigate their vibrational properties in the solid phase, specifically focusing on the amide‐type normal modes of vibrations. Furthermore, the crystal structures of three derivatives were determined by single‐crystal X‐ray diffraction, which provided insights into their molecular arrangements. The occurrence of N−H⋅⋅⋅O=C hydrogen bonding intermolecular interaction is clearly observed and characterized by Hirschfeld surface analysis. Topology analysis using the Quantum Theory of Atom in Molecules and Crystals (QTAIM−C) were employed to investigate the electronic properties of the isolated amide molecules and to analyse the intermolecular interactions within the crystalline structure. The periodic calculations for the crystal revealed a higher electronic density in the C−N bond, indicating an increased covalent character in this bond compared with the C=O bond. This observation indicates the presence of resonance‐assisted hydrogen bonds within the amide core, leading to π electronic delocalization. [ABSTRACT FROM AUTHOR]

The title compound is synthesized by addition of solid Tl2CO3 to a boiling solution of H2C2O4 in H2O (10 min, 75% yield) and characterized by single crystal XRD, FTIR, and FT Raman spectroscopy. [ABSTRACT FROM AUTHOR]

Two Schiff bases derived from o -vanillin ( o- HVA), a well-known antioxidant hydroxo aldehyde, have been obtained from condensation with 2-thiophenecarboxilic acid hydrazide (TPNNH) and 2-thiophenemethylamine (TPNH2), respectively. The inclusion of thiophene is based on its significance in the development of effective therapeutic agents. The study of the compounds oVATPNNH and oVATPNH2 includes solid state structural and spectroscopic analysis by single-crystal X-ray diffraction and vibrational spectroscopy (FTIR and Raman). The crystal structure of oVATPNH2 shows a peculiar rotational disorder in the heterocycle. Tautomeric equilibria in solution, which depends on the molecule structure and the nature of the solvent, were analysed by means of 1 H and 13 C{ 1 H} NMR along with electronic spectroscopy. Tautomerism plays an important role not only in the molecular interactions but also in the behaviour of the Schiff base when acting as a ligand in coordination compounds. Results obtained from DFT calculations were used in the interpretation of the experimental data and in the spectral assignments. [ABSTRACT FROM AUTHOR]

Coumarins (2H-chromen-2-one) are oxygen-containing heterocyclic compounds that belong to the benzopyranones family. In this work we have synthesized different coordination complexes with coumarin-3-carboxylic acid (HCCA), o-phenanthroline (phen) and zinc(II). In the reported [Zn(CCA) 2 (H 2 O) 2 ] complex, coumarin-3-carboxylate (CCA) is acting as a bidentate ligand while in the two prepared complexes, [Zn(phen) 3 ]CCA(NO 3 ) (obtained as a single crystal) and [Zn(CCA) 2 phen].4H 2 O, CCA is acting as a counterion of the complex cation [Zn(phen) 3 ] +2 or coordinated to the metal center along with phen, respectively. These compounds were characterized on the basis of elemental analysis and thermogravimetry. NMR, FTIR and Raman spectroscopies of the compounds and the CCA potassium salt (KCCA) allow to determine several similarities and differences among them. Finally, their behavior against alkaline phosphatase enzyme and their antimicrobial activities were also measured. [ABSTRACT FROM AUTHOR]

The intermolecular interactions in the solid state and the spectroscopic vibrational, electronic and NMR properties of new 3-methyl-substituted-2-trifluoromethylchromone derivatives with –CN (1), –NO2 (2), –OH (3) and –NH2 (4) groups were discussed with the assistance of DFT calculations. The crystal structures of compounds 1–3 were determined by X-ray diffraction showing molecular ribbons for compounds 1 and 2, and dimers via O–H…O=C hydrogen bonds for 3. Hirshfeld surfaces and the corresponding fingerprint plots, as well as the electrostatic potentials mapped on the surfaces revealed C–H…O and C–H…F hydrogen bonds, and π…π stacking as the main cooperative driving forces for building supramolecular architectures in all compounds. The C–H…π and C=O…π interactions also contribute to stabilizing the crystal structures of 1 and 2. A further analysis of Hirshfeld surfaces was performed using the enrichment ratio as a new descriptor to determine the likelihood of chemical species to establish specific interactions in the molecular packing. The lattice energies of the crystal structures and several intermolecular contacts present in different molecular pairs were also quantified. Molecular docking studies showed the interaction of the title compounds with the catalytic site of PLA2 (PDB code URL URL="HTTP://XLINK.RSC.ORG/?PDB=2QOG"2QOG/URL) from Crotalus durissus terrificus, and suggested that the investigated compounds could inhibit toxic effects of snake venom. [ABSTRACT FROM AUTHOR]

Three novel zinc and cadmium complexes with 1-methylimidazole and 2-methylimidazole as ligands, mono-nuclear dichloro-bis(1-methylimidazole) zinc(II) and dibromo-bis(2-methylimidazole)cadmium(II) monohydrate complexes, and poly-nuclear bis(1-methylimidazole)-di-(μ2-bromo)cadmium(II) complex, namely, compounds 1 – 3 , respectively, have been synthesized. The complexes were characterized by IR and Raman spectroscopies, thermal analysis and fluorescence. All the compounds exhibit interesting luminescent properties in solid state originated from intra-ligand (π→π*) transitions. Crystal structures of 1 – 3 were determined by single-crystal X-ray diffraction. Compound 1 crystallizes in P 2 1 / n space group, the Zn(II) ion lies at a crystal general position in a tetrahedral environment, and the mono-nuclear units are weakly bonded to one another by C H ⋯ Cl hydrogen bonds. Compound 2 crystallizes in Pnma space group, and mirror-related tetrahedral units around Cd(II) ion are H-bonded through a water molecule. Compound 3 crystallizes in P 2 1 / c space group, and the Cd(II) ion presents a centrosymmetric octahedral coordination. Neighboring and equatorial edge-sharing octahedra conform a polymeric arrangement that extends along the crystal a -axis. Weak hydrogen bonds are the major driving forces in the crystal packing of the three complexes. Hirshfeld surface analysis reveals a detailed scrutiny of intermolecular interactions experienced by each complex. The surfaces mapped over d norm property highlight the X···H (X = Cl, Br) as the main intermolecular contacts for the three complexes, being also relevant the presence of O ⋯ H contacts for complex 2 . The surfaces mapped over Shape index and curvedness properties for the two Cd complexes allow identify π … π stacking interactions which are absent in the Zn complex. 2D fingerprint plots have been used to quantify the relative contribution of the intermolecular contacts to crystal stability of compounds, showing the crucial importance of weak interactions in building different supramolecular architectures. Furthermore, molecular electrostatic potentials for visualizing and quantifying the attractive character of interactions were calculated. [ABSTRACT FROM AUTHOR]

A family of hydrazones of isoniazid and a group of hydroxybenzalaldehydes (vanillin, 5-bromovanillin, 5-chlorosalicylaldehyde and 5-bromosalicylaldehyde) were obtained and fully characterized. The results, including theoretical data, are comparatively analyzed along with the already reported hydrazone of o -vanillin. The crystal structures of three compounds were determined. The hydrazones obtained from halogenated aldehydes are isomorphic and chiral to each other. Structures are further stabilized by (pyr)NH + ⋯Cl − and OwH⋯Cl − bonds. The vanillin hydrazone shows a conformer that differs from the previously reported. Neighboring molecules are linked to each other through OH⋯N(pyr) bonds, giving rise to a nearly planar polymeric structure. The conformational space was searched and geometries were optimized both in the gas phase and including solvent effects by DFT. Results are extended to describe the 5-bromovanillin hydrazone. FTIR, NMR and electronic spectra were measured and assigned with the help of computational calculations. [ABSTRACT FROM AUTHOR]

Chagas' disease (American Trypanosomiasis) is an ancient and endemic illness in Latin America caused by the protozoan parasite Trypanosoma cruzi. Although there is an urgent need for more efficient and less toxic chemotherapeutics, no new drugs to treat this disease have entered the clinic in the last decades. Searching for metal-based prospective antichagasic drugs, in this work, multifunctional Re(I) tricarbonyl compounds bearing two different bioactive ligands were designed: a polypyridyl NN derivative of 1,10-phenanthroline and a monodentate azole (Clotrimazole CTZ or Ketoconazol KTZ). Five fac-[Re(CO)3(NN)(CTZ)](PF6) compounds and a fac-[Re(CO)3(NN)(KTZ)](PF6) were synthesized and fully characterized. They showed activity against epimastigotes (IC50 3.48–9.42 μM) and trypomastigotes of T. cruzi (IC50 0.61–2.79 μM) and moderate to good selectivity towards the parasite compared to the VERO mammalian cell model. In order to unravel the mechanism of action of our compounds, two potential targets were experimentally and theoretically studied, namely DNA and one of the enzymes involved in the parasite ergosterol biosynthetic pathway, CYP51 (lanosterol 14-α-demethylase). As hypothesized, the multifunctional compounds shared in vitro a similar mode of action as that disclosed for the single bioactive moieties included in the new chemical entities. Additionally, two relevant physicochemical properties of biological interest in prospective drug development, namely lipophilicity and stability in solution in different media, were determined. The whole set of results demonstrates the potentiality of these Re(I) tricarbonyls as promising candidates for further antitrypanosomal drug development. [ABSTRACT FROM AUTHOR]

The potassium salt of the Schiff base obtained by condensation of 2-hydroxy-3-methoxybenzaldehyde (o-vanillin) and 2-aminoethanesulfonic acid (taurine) in a methanol potassium hydroxide solution was characterized by crystallographic, spectroscopic and DFT methods. The compound crystallizes in the monoclinic C2/c space group with a = 37.539(4), b = 5.9129(4), c = 26.321(5) Å, β = 121.10(2)° and Z = 8 molecules per unit cell. The crystallographic data reveal that two different anionic molecules, which constitute a tautomeric pair, coexist in the crystal. This finding is supported by FTIR, Raman and electronic measurements in methanol solution. The main crystallographic differences between the bonding structures occur along the shortest chemical path linking the oxygen and the nitrogen atom of the OH and CN group. Both tautomeric forms are stabilized by strong O–H…N and N–H…O intramolecular hydrogen bonds. Optimized geometrical parameters and calculated spectroscopic features obtained by DFT calculations show a very good agreement with the experimental data. Moreover, 1H NMR, 13C NMR and electronic measurements in DMSO solution show the prevalence of the enol-imine tautomer in this solvent. [ABSTRACT FROM AUTHOR]

• A galactosyl isoxazoline has been prepared by phenyl nitrile oxide cycloaddition. • The two diastereomeric isoxazolines have been spontaneously resolved by crystallization. • Conformational behavior of both diastereomers has been studied in solution and the crystalline form. In this study, a glycosyl isoxazoline has been prepared by cycloaddition of phenyl nitrile oxide to 6- O -allyl galactopyranose. Crystallization of the galactosyl isoxazoline resulted in the spontaneous resolution of its two diastereomers. Their conformational behavior has been studied in solution and in crystalline form by NMR and X-ray diffraction analysis showing that both diastereomers have essentially the same O S 2 conformation. To complete the study of the diastereomeric isoxazolines, Density Functional Theory was applied. The theoretical and experimental 1H NMR, as well as 13C NMR chemical shifts, showed very good correlation. Furthermore, structures resulting from X-ray analysis provided excellent starting points for DFT calculations. [Display omitted] Spontaneous resolution of diastereomeric glycosyl isoxazolines: a combined theoretical and experimental study in solution and in the crystalline form. [ABSTRACT FROM AUTHOR]

Two novel Re(i) complexes with the general formula fac-[Re(CO)3(L)(nHo)]CF3SO3, where L = 2,2′-bipyridine (bpy) or 1,10 phenanthroline (phen) and nHo (9H-pyrido[3,4-b]indole; norharmane) have been synthesized. The Re(i)–nHo complexes were characterized by structural X-ray diffraction, 1H and 13C NMR, UV-vis absorption and FT-IR spectroscopy, and by a combination of two mass spectrometry techniques, namely ESI-MS and UV-MALDI-MS. All characterizations showed that nHo is coordinated to the metal atom by the pyridine nitrogen of the molecule. X-ray structural analysis revealed that the crystal lattices for both complexes are further stabilized by a strong ＞N–H…O bond between the pyrrole NH group of the pyridoindole ligand and one oxygen atom of the trifluoromethanesulfonate counter-ion. Ground state geometry optimization by DFT calculations showed that in fluid solution the nHo ligand may rotate freely. The nature of the electronic transitions of Re(CO)3(bpy)(nHo)+ were established by TD-DFT calculations. The set of the most important electronic transitions present in this complex are comprised of π→π* electronic transitions centered on bpy and nHo moieties, LLCTnHo→COs, MLLCTRe(CO)3→bpy and LLCTnHo→bpy transitions. Additionally, TD-DFT calculations predict the existence of another two intense MLLCTRe(CO)3→nHo electronic transitions. Calculated UV-vis absorption spectra are in good agreement with the corresponding experimental data for the bpy-containing complex. [ABSTRACT FROM AUTHOR]

The ammonium, barium hexacyanoferrate(II) trihydrate, Ba(NH)[Fe(CN)]·3HO, has been synthesized for the first time, was characterized by thermogravimetric and differential thermal analysis (TG-DTA), infrared (IR) and Raman spectroscopy and chemical analysis, and its crystal and molecular structures were determined by X-ray diffraction methods. The chemical composition was determined by assaying Ba(II) with EDTA, ammonia nitrogen with Nessler's reagent as indicator and Fe(II) using spectrophotometry with ortho-phenanthroline method. The hydration number was estimated by thermogravimetric analysis. The compound crystallizes in the trigonal R-3 c space group. The ferrocyanide anion has an almost perfect octahedral shape with its Fe(II) ion in a crystallographic special position of point symmetry S [d(Fe-C) = 1.912(2) Å, d(C-N) = 1.153(3) Å]. The barium, ammonium nitrogen and water oxygen atoms are also at lattice special positions with site symmetries D, C and C, respectively. The thermal decomposition process was also studied using TG-DTA, and the products of decomposition were identified by IR spectroscopy. It proposes a mechanism of decomposition. [ABSTRACT FROM AUTHOR]

Five Schiff bases obtained from condensation of 4-methoxybenzohydrazide with related aldehydes, namely o -vanillin, vanillin, 5-bromovanillin, 5-chlorosalicylaldehyde and 5-bromosalicylaldehyde were prepared. A detailed structural and spectroscopic study is reported. The crystal structures of four members of the family were determined and compared with one another. The hydrazones obtained from 5-chlorosalicylaldehyde and 5-bromosalicylaldehyde resulted to be isomorphic to each other. The solid-state structures are stabilized by intra-molecular O H⋯N interactions in salicylaldehyde derivatives between the O H moiety from the aldehyde and the hydrazone nitrogen atom. All crystals are further stabilized by inter-molecular H-bonds mediated by the crystallization water molecule. A comparative analysis between experimental and theoretical results is presented. The conformational space was searched and geometries were optimized both in gas phase and including solvent effects. The structure is predicted for the compound for which the crystal structure was not determined. Infrared and electronic spectra were measured and assigned with the help of data obtained from computational methods based on the Density Functional Theory. [ABSTRACT FROM AUTHOR]

The crystal structures of bis[1-ethyl-6-fluoro-4-oxo-7-(piperazin-1-ium-4-yl)-1,4- dihydroquinoline-3-carboxylato]copper(II) sulfate heptahydrate, [Cu(C16H18FN3O3) 2]SO4.7H2O or [Cu(nor)2]SO4.7H2O (nor is norfloxacin), and bis{1-[2- (ethylsulfonyl)ethyl]-2-methyl-5-nitroimide}dinitratocopper(II), [Cu(NO3)2- (C8H13N3O4S)2] or [Cu(NO3)2(tnz)2] (tnz is tinidazole), were solved by X-ray diffraction. Both complexes crystallize in the space group P21/c, with Z = 4 (for nor) and Z = 2 (for ntz) molecules per unit cell. In [Cu(nor)2]SO4.7H2O, the CuII ion is at the centre of a square-planar environment, trans coordinated to two independent norfloxacin molecules in the zwitterionic form acting as bidentate ligands through one of the carboxyl (cbx) and the carbonyl (cb) O atoms. The solid is further stabilized by an extensive network of N--H. . .O(sulfate), N--H. . .O(cbx), N--H. . .OW, OW--H. . .O(sulfate) and OW--H. . .OW hydrogen bonds. The [Cu(NO3)2(tnz)2] complex is centrosymmetric, with the CuII ion in a square planar environment, coordinated to a tinidazole molecule acting as a monodentate ligand through its imidazole N atom and to one nitrate O atom. The vibrational FT-IR absorption spectra and thermal behaviour of the complexes were also studied and are briefly discussed based on the crystal structures. [ABSTRACT FROM AUTHOR]

The crystal structures of bis[1‐ethyl‐6‐fluoro‐4‐oxo‐7‐(piperazin‐1‐ium‐4‐yl)‐1,4‐dihydroquinoline‐3‐carboxylato]copper(II) sulfate heptahydrate, [Cu(C16H18FN3O3)2]SO4·7H2O or [Cu(nor)2]SO4·7H2O (nor is norfloxacin), and bis{1‐[2‐(ethylsulfonyl)ethyl]‐2‐methyl‐5‐nitroimide}dinitratocopper(II), [Cu(NO3)2(C8H13N3O4S)2] or [Cu(NO3)2(tnz)2] (tnz is tinidazole), were solved by X‐ray diffraction. Both complexes crystallize in the space group P21/c, with Z = 4 (for nor) and Z = 2 (for ntz) molecules per unit cell. In [Cu(nor)2]SO4·7H2O, the CuII ion is at the centre of a square‐planar environment, trans coordinated to two independent norfloxacin molecules in the zwitterionic form acting as bidentate ligands through one of the carboxyl (cbx) and the carbonyl (cb) O atoms. The solid is further stabilized by an extensive network of N—H…O(sulfate), N—H…O(cbx), N—H…OW, OW—H…O(sulfate) and OW—H…OW hydrogen bonds. The [Cu(NO3)2(tnz)2] complex is centrosymmetric, with the CuII ion in a square planar environment, coordinated to a tinidazole molecule acting as a monodentate ligand through its imidazole N atom and to one nitrate O atom. The vibrational FT–IR absorption spectra and thermal behaviour of the complexes were also studied and are briefly discussed based on the crystal structures.The structural, spectroscopic and thermal characterization of the novel compounds [Cu(norfloxacin)2]SO4·7H2O and [Cu(NO3)2(tinidazole)2] with potential use as antimicrobial agents is presented. [ABSTRACT FROM AUTHOR]

A series of 2-(haloalkyl)-3-azidomethyl and 6-azido chromones has been synthetized, characterized and studied by theoretical (DFT calculations) and spectroscopic methods (UV-Vis, NMR). The crystal structure of 3-azidomethyl-2-difluoromethyl chromone, determined by X-ray diffraction methods, shows a planar framework due to extended π-bond delocalization. Its molecular packing is stabilized by F···H, N···H and O···H hydrogen bonds, π···π stacking and C–O···π intermolecular interactions. Moreover, AIM, NCI and Hirshfeld analysis evidenced that azido moiety has a significant role in the stabilization of crystal packing through weak intermolecular interactions, where analysis of electronic density suggested closed-shell (CS) interatomic interactions. [ABSTRACT FROM AUTHOR]

• Synthesis of three novel antipyrine-amide derivatives confirmed by spectroscopic analysis. • Molecular and crystal structures for the three compounds were established by single-crystal X- ray analysis. • Hirshfeld surface analysis shows dominance of hydrogen bonds promoted by the N H group. • FTIR, Raman, and DFT analyses describe vibrational properties of the compounds. • Topological QTAIM and NCIplot analysis reveal significant noncovalent C H···π and Cl···π interactions. In this study, we report the synthesis, structural characterization by X-ray diffraction, vibrational (Infrared and Raman) investigation, Hirshfeld surface analysis, and DFT calculations of three new antipyrine derivatives (1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1 H -pyrazol-4-yl) bearing amide groups (1–3). The compounds were synthesized in good yields and characterized spectroscopically. X-ray diffraction revealed that compound 1 crystallizes as a monohydrate in the monoclinic space group P 2 1 /c, while compound 3 also crystallizes as a monohydrate in the orthorhombic space group P ccn, exhibiting quasi-isomorphism with 1. Compound 2 crystallizes in the P 2 1 /c space group, forming H-bonded centrosymmetric dimers. The crystal packing is stabilized by N H···O and C H···O hydrogen bonds, along with C H···π interactions. FTIR and Raman spectroscopic analysis, supported by DFT calculations, identified key vibrational modes in the amide and pyrazole moieties. Hirshfeld surface analysis indicated that the molecular sheets are primarily formed by hydrogen bonds, with stabilization dominated by electrostatic energy contributions. DFT calculations (PBE0-D3/def2-TZVP) and QTAIM/NCIplot analyses revealed that the H-bonding interactions are energetically significant. [ABSTRACT FROM AUTHOR]

Structural and conformational properties of two dixanthogen molecules, [CH3(CH2)2OC(S)S]2 and [(CH3)2CHOC(S)S]2, have been analyzed using a combined experimental and theoretical approach, with data obtained from structural X-ray diffraction methods, IR, Raman and UV-visible spectroscopies, and DFT calculations. [(CH3)2CHOC(S)S]2 crystallizes in the monoclinic P21/c space group with a = 9.735(1) Å, b = 12.588(3) Å, c = 12.131(2) Å, β = 112.65(1)°, and Z = 4 molecules per unit cell. The interactions in the crystal were modelled and interpreted by NBO analysis. [CH3(CH2)2OC(S)S]2 is liquid at room temperature, and the vibrational spectra were satisfactorily explained in terms of the equilibrium between three conformers, originating from the rotation of the two terminal CH3– groups, in agreement with the DFT predictions. The electronic spectra of both dixanthogens were assigned with the assistance of the TD-DFT calculations. [ABSTRACT FROM AUTHOR]

Highlights: [•] Disulfide Schiff base from condensation of 2-aminothiophenol and o-vanillin. [•] X-ray diffraction crystal structures of the anhydrous and monohydrate forms. [•] Vibrational and electronic spectra assigned with the help of DFT calculations. [Copyright &y& Elsevier]